Portable printers are widely used in various applications such as home delivery services and inventory management. A portable printer is disclosed in, for example, JP-A-08-300740 (Document 1). As one of forms of use, the portable printer disclosed in Document 1 stores a label sheet attached with a base sheet wound in a roll shape, applies printing based on accumulated print data to labels stuck to the base sheet while drawing out the label sheet, peels off a printed label from the base sheet, and issues the label from an issue port.
In the past, the portable printer of this type determines a print start position by feeding the label sheet by a distance equivalent to one label when a power supply is turned on. This is because, in the portable printer of this type, since a stop position of the label sheet (i.e., a print start position at the time of power-on) is unknown when the power supply is turned off, a shift often occurs in a print position if printing is started in that state when the power supply is turned on.
However, it is extremely wasteful to feed the label sheet by the distance equivalent to one label every time the power supply is turned on. In particular, in the portable printer used in the home delivery services and the like, since the power supply tends to be turned on and off many times, the number of wasted labels tends to increase.
It is also conceivable to determine the print start position by back-feeding the label sheet and then feeding the label sheet by the distance equivalent to one label when the power supply is turned on. However, for example, when the length of the short side of the label stuck to the base sheet of the label sheet is small, the label comes off the base sheet according to the back-feed and a jam occurs.
The present invention has been devised in view of the above and it is an object of the present invention to provide a printer and a method of determining a print start position with which labels stuck to a base sheet of a label sheet are not wasted when a print start position is determined compared with the portable printer in the past that always feeds the label sheet by the distance equivalent to one label in order to determine a print start position.